My changes are missing after simultaneously editing with other authors

Cause: Another author may have rejected your changes and saved the presentation to the server after you did.

Solution: If you still have the presentation open with your changes, try saving your changes to the server again.

Whenever an author saves the presentation, their changes are saved to the server, and any changes from others that they rejected during a comparison are discarded. If you still have the presentation with your changes open and the Updates Available menu is displayed on the bottom bar, you can save your changes to the server again.

On the Updates Available menu, click Save and Review.

If you and another author both made a change to the same item then a conflict may occur and you will be prompted to review the conflict to decide which change to accept or reject.

To avoid having another author reject your changes again later, try the following solutions.

Send an instant message or e-mail to the other authors letting them know about the changes you want to keep.
Ask the other authors to close the presentation, and then check out the presentation so you can edit it separately. For more information, see Check out a file located on SharePoint.

Solution: Make your changes in the presentation again.

Whenever an author saves the presentation, their changes are saved to the server, and any changes from others that they rejected during a comparison are discarded. If you closed the presentation before the other author saved the presentation (and discarded your changes), you might be able to recover your changes if they were saved in an earlier version of the presentation.

To avoid having another author reject your changes again later, try the following solutions.

Send an instant message or e-mail to the other authors letting them know about the changes you want to keep.
Ask the other authors to close the presentation, and then check out the presentation so you can edit it separately. For more information, see Check out a file located on SharePoint.

Solution: Check for an earlier version of the presentation on the server.

However, if you go back to an earlier version, you may lose changes that were saved in a later version.

If you decide to go back to an earlier version, do the following:

Find the earlier version on the server, and then save the presentation on your computer.
Find the most up-to-date version of the presentation on the server, and then save the presentation to your computer.
Open one presentation and compare it with the other so you can review the changes and decide which to accept or reject. For more information about combining two presentations, see Combine two presentations.
When you have finished reviewing the changes, end the comparison, and then save the presentation.
Save the presentation to the server again, and overwrite the most up-to-date version.

Cause: The presentation may not have been saved to the server because of an error.

Solution: Check the upload status of the presentation in Upload Center.

If the presentation has a status of upload pending or upload failed in Upload Center, then your changes have not been saved to the server. For more information, see I can’t save my file to SharePoint or SkyDrive.

To check the upload status:

In the Finder, open /Applications/Microsoft Office 2011/Office/Microsoft Upload Center.

Cause: You might have saved the presentation on your computer instead of the server.

Solution: Search for the presentation on your computer.

If you find a copy of the presentation on your computer, you can compare it with the most up-to-date version on the server, and then combine your changes, if needed.

Find the most up-to-date version of the presentation on the server, and then save the presentation to your computer.
Open one presentation and compare it with the other so you can review the changes and decide which to accept or reject. For more information about combining two presentations, see Combine two presentations.
When you have finished reviewing the changes, end the comparison, and then save the presentation.
Save the presentation to the server again, and overwrite the most up-to-date version.